Heat oven to 350º F. Combine the pumpkin puree, sugar, cinnamon, and ½ teaspoon of the salt in a small bowl.
Roll the puff pastry into two 16-inch squares on floured work surface. Cut into 16 4-by-4 inch pieces using a pizza cutter or chefs knife. Prick each square with a fork.
Spread the pumpkin mixture on half of the pieces, dividing evenly, and leaving a ½-inch border all around. Crimp the edges with a fork. Transfer a baking sheet and refrigerate for 30 minutes.
Bake, rotating the baking sheets halfway though, until golden brown, 25 to 30 minutes. Transfer to a wire rack to cool.
Beat the cream cheese, powdered sugar, butter, and the remaining pinch of salt with an electric mixer in a medium bowl until smooth, 1 to 2 minutes.
Spread the pop tarts with the glaze, dividing evenly.